Document And Entity Information
v3.7.0.1
Document And Entity Information
Total
Risk/Return:  
Document Type 485BPOS
Document Period End Date Dec. 31, 2016
Registrant Name FENIMORE ASSET MANAGEMENT TRUST
Central Index Key 0000797136
Amendment Flag false
Document Creation Date Apr. 28, 2017
Document Effective Date May 01, 2017
Prospectus Date May 01, 2017

Risk_Return Summary - (FAM Value Fund Investor Shares)
v3.7.0.1
Investor Shares [Member] | FAM Value Fund
Shareholder Fees - {FAM Value Fund Investor Shares}
Investor Shares [Member]
FAM Value Fund
Investor Class
Maximum sales charge (load) on purchase none
Maximum deferred sales charge (load) none
Redemption fee none
Annual Fund Operating Expenses - {FAM Value Fund Investor Shares}
Investor Shares [Member]
FAM Value Fund
Investor Class
Management Fees 0.90%
Distribution and Service (12b-1) Fees none
Other Expenses 0.29%
Acquired Fund Fees and Expenses 0.01% [1]
Total Fund Operating Expenses 1.20% [1]
Fee Waiver/Expense Reimbursement (0.01%) [1]
Net Fund Operating Expenses 1.19%
[1] The Advisor has contractually agreed, until May 1, 2018, to waive fees and/or reimburse the Fund certain expenses (excluding interest, taxes, brokerage costs, Acquired Fund Fees and Expenses, dividend expense and extraordinary expenses) to the extent necessary to maintain Net Fund Operating Expenses for Investor Shares at 1.18%. The Fund has agreed to repay the Advisor for amounts waived or reimbursed by the Advisor pursuant to the Expense Limitation Agreement provided that such repayment does not cause the Net Fund Operating Expenses for Investor Shares to exceed the above limit and the repayment is made within three years after the year in which the Advisor incurred the expense. This Expense Limitation Agreement may only be amended or terminated by the Fund's Board of Trustees.
Expense Example- {FAM Value Fund Investor Shares}
1 Year
3 Years
5 Years
10 Years
Investor Shares [Member] | FAM Value Fund | Investor Class | USD ($) 121 380 659 1,454
Bar Chart

  

Best Quarter 4Q'11 13.34%

 Worst Quarter

4Q'08 

-20.68%

 


Average Annual Total Returns- {FAM Value Fund Investor Shares} - Investor Shares [Member] - FAM Value Fund - Investor Class
1 Year
5 Years
10 Years
Before Taxes 15.60% 13.79% 6.75%
after taxes on distributions 14.46% 12.66% 6.03%
after taxes on distributions and sale of fund shares 10.54% 11.43% 5.56%
Russell MidCap Index 13.80% 14.72% 7.86%

Risk_Return Detail Data - (FAM Value Fund Investor Shares)
v3.7.0.1
Label Element Value
Risk/Return: rr_RiskReturnAbstract  
Registrant Name dei_EntityRegistrantName FENIMORE ASSET MANAGEMENT TRUST
Prospectus Date rr_ProspectusDate May 01, 2017
Investor Shares [Member] | FAM Value Fund | Investor Class  
Risk/Return: rr_RiskReturnAbstract  
Maximum sales charge (load) on purchase rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
Maximum deferred sales charge (load) rr_MaximumDeferredSalesChargeOverOther none
Redemption fee rr_RedemptionFeeOverRedemption none
Management Fees rr_ManagementFeesOverAssets 0.90%
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Other Expenses rr_OtherExpensesOverAssets 0.29%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.01% [1]
Total Fund Operating Expenses rr_ExpensesOverAssets 1.20% [1]
Fee Waiver/Expense Reimbursement rr_FeeWaiverOrReimbursementOverAssets (0.01%) [1]
Net Fund Operating Expenses rr_NetExpensesOverAssets 1.19%
1 Year rr_ExpenseExampleYear01 $ 121
3 Years rr_ExpenseExampleYear03 380
5 Years rr_ExpenseExampleYear05 659
10 Years rr_ExpenseExampleYear10 $ 1,454
Annual Return 2007 rr_AnnualReturn2007 (0.79%)
Annual Return 2008 rr_AnnualReturn2008 (28.68%)
Annual Return 2009 rr_AnnualReturn2009 22.18%
Annual Return 2010 rr_AnnualReturn2010 17.02%
Annual Return 2011 rr_AnnualReturn2011 (0.41%)
Annual Return 2012 rr_AnnualReturn2012 11.39%
Annual Return 2013 rr_AnnualReturn2013 32.96%
Annual Return 2014 rr_AnnualReturn2014 13.41%
Annual Return 2015 rr_AnnualReturn2015 (1.74%)
Annual Return 2016 rr_AnnualReturn2016 15.60%
Highest Quarterly Return, Label rr_HighestQuarterlyReturnLabel Best Quarter
Highest Quarterly Return, Date rr_BarChartHighestQuarterlyReturnDate Dec. 31, 2011
Highest Quarterly Return rr_BarChartHighestQuarterlyReturn 13.34%
Lowest Quarterly Return, Label rr_LowestQuarterlyReturnLabel Worst Quarter
Lowest Quarterly Return, Date rr_BarChartLowestQuarterlyReturnDate Dec. 31, 2008
Lowest Quarterly Return rr_BarChartLowestQuarterlyReturn (20.68%)
1 Year rr_AverageAnnualReturnYear01 15.60%
5 Years rr_AverageAnnualReturnYear05 13.79%
10 Years rr_AverageAnnualReturnYear10 6.75%
Investor Shares [Member] | FAM Value Fund | Investor Class | after taxes on distributions  
Risk/Return: rr_RiskReturnAbstract  
1 Year rr_AverageAnnualReturnYear01 14.46%
5 Years rr_AverageAnnualReturnYear05 12.66%
10 Years rr_AverageAnnualReturnYear10 6.03%
Investor Shares [Member] | FAM Value Fund | Investor Class | after taxes on distributions and sale of fund shares  
Risk/Return: rr_RiskReturnAbstract  
1 Year rr_AverageAnnualReturnYear01 10.54%
5 Years rr_AverageAnnualReturnYear05 11.43%
10 Years rr_AverageAnnualReturnYear10 5.56%
Investor Shares [Member] | FAM Value Fund | Investor Class | Russell MidCap Index  
Risk/Return: rr_RiskReturnAbstract  
1 Year rr_AverageAnnualReturnYear01 13.80%
5 Years rr_AverageAnnualReturnYear05 14.72%
10 Years rr_AverageAnnualReturnYear10 7.86%
Investor Shares [Member] | FAM Value Fund  
Risk/Return: rr_RiskReturnAbstract  
Risk/Return [Heading] rr_RiskReturnHeading
Objective [Heading] rr_ObjectiveHeading
Objective, Primary [Text Block] rr_ObjectivePrimaryTextBlock
Expense [Heading] rr_ExpenseHeading
Expense Narrative [Text Block] rr_ExpenseNarrativeTextBlock
Shareholder Fees Caption [Text] rr_ShareholderFeesCaption
Operating Expenses Caption [Text] rr_OperatingExpensesCaption
Fee Waiver or Reimbursement over Assets, Date of Termination rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination May 1, 2018
Portfolio Turnover [Heading] rr_PortfolioTurnoverHeading
Portfolio Turnover [Text Block] rr_PortfolioTurnoverTextBlock
Portfolio Turnover, Rate rr_PortfolioTurnoverRate 4.25%
Expense Example [Heading] rr_ExpenseExampleHeading
Expense Example Narrative [Text Block] rr_ExpenseExampleNarrativeTextBlock
Expense Example by, Year, Caption [Text] rr_ExpenseExampleByYearCaption
Strategy [Heading] rr_StrategyHeading
Strategy Narrative [Text Block] rr_StrategyNarrativeTextBlock
Risk [Heading] rr_RiskHeading
Risk Narrative [Text Block] rr_RiskNarrativeTextBlock
Risk Lose Money [Text] rr_RiskLoseMoney the value of your investment will go up and down, which means that you could lose money.
Bar Chart and Performance Table [Heading] rr_BarChartAndPerformanceTableHeading
Performance Narrative [Text Block] rr_PerformanceNarrativeTextBlock
Performance Information Illustrates Variability of Returns [Text] rr_PerformanceInformationIllustratesVariabilityOfReturns The bar chart shows changes in the Investor Shares performance since 2007. The table shows the Investor Shares average annual returns (before and after taxes ) for the one year, five year and ten year periods compared to those of the Russell MidCap Index, the Fund's primary benchmark index.
Performance Availability Website Address [Text] rr_PerformanceAvailabilityWebSiteAddress famfunds.com
Performance Past Does Not Indicate Future [Text] rr_PerformancePastDoesNotIndicateFuture The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.
Bar Chart Closing [Text Block] rr_BarChartClosingTextBlock

  

Best Quarter 4Q'11 13.34%

 Worst Quarter

4Q'08 

-20.68%

 


Performance Table Heading rr_PerformanceTableHeading
Performance Table Uses Highest Federal Rate rr_PerformanceTableUsesHighestFederalRate The after-tax returns shown in the table are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.
Performance Table Not Relevant to Tax Deferred rr_PerformanceTableNotRelevantToTaxDeferred Actual after-tax returns depend on the investor's tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold their Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts, or to investors who are tax exempt.
Performance Table Narrative rr_PerformanceTableNarrativeTextBlock
[1] The Advisor has contractually agreed, until May 1, 2018, to waive fees and/or reimburse the Fund certain expenses (excluding interest, taxes, brokerage costs, Acquired Fund Fees and Expenses, dividend expense and extraordinary expenses) to the extent necessary to maintain Net Fund Operating Expenses for Investor Shares at 1.18%. The Fund has agreed to repay the Advisor for amounts waived or reimbursed by the Advisor pursuant to the Expense Limitation Agreement provided that such repayment does not cause the Net Fund Operating Expenses for Investor Shares to exceed the above limit and the repayment is made within three years after the year in which the Advisor incurred the expense. This Expense Limitation Agreement may only be amended or terminated by the Fund's Board of Trustees.

Risk_Return Summary - (FAM Equity-Income Fund Investor Shares)
v3.7.0.1
Investor Shares [Member] | FAM Equity-Income Fund
Shareholder Fees - {FAM Equity-Income Fund Investor Shares}
Investor Shares [Member]
FAM Equity-Income Fund
Investor Class
Maximum sales charge (load) on purchase none
Maximum deferred sales charge (load) none
Redemption fee none
Annual Fund Operating Expenses - {FAM Equity-Income Fund Investor Shares}
Investor Shares [Member]
FAM Equity-Income Fund
Investor Class
Management Fees 0.90%
Distribution and Service (12b-1) Fees none
Other Expenses 0.36%
Acquired Fund Fees and Expenses 0.01%
Total Fund Operating Expenses 1.27%
Expense Example- {FAM Equity-Income Fund Investor Shares}
1 Year
3 Years
5 Years
10 Years
Investor Shares [Member] | FAM Equity-Income Fund | Investor Class | USD ($) 129 403 697 1,534
Bar Chart


  

Best Quarter 2Q'09 16.68%

 

Worst Quarter

4Q'08 -21.88%

 

Average Annual Total Returns- {FAM Equity-Income Fund Investor Shares} - Investor Shares [Member] - FAM Equity-Income Fund - Investor Class
1 Year
5 Years
10 Years
Before Taxes 21.59% 13.41% 6.93%
after taxes on distributions 18.93% 11.71% 5.74%
after taxes on distributions and sale of fund shares 14.30% 10.61% 5.34%
Russell MidCap Index 13.80% 14.72% 7.86%

Risk_Return Detail Data - (FAM Equity-Income Fund Investor Shares)
v3.7.0.1
Label Element Value
Risk/Return: rr_RiskReturnAbstract  
Registrant Name dei_EntityRegistrantName FENIMORE ASSET MANAGEMENT TRUST
Prospectus Date rr_ProspectusDate May 01, 2017
Investor Shares [Member] | FAM Equity-Income Fund | Investor Class  
Risk/Return: rr_RiskReturnAbstract  
Maximum sales charge (load) on purchase rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
Maximum deferred sales charge (load) rr_MaximumDeferredSalesChargeOverOther none
Redemption Fee (as a percentage of Amount Redeemed) rr_RedemptionFeeOverRedemption none
Management Fees (as a percentage of Assets) rr_ManagementFeesOverAssets 0.90%
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Other Expenses rr_OtherExpensesOverAssets 0.36%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.01%
Total Fund Operating Expenses rr_ExpensesOverAssets 1.27%
1 Year rr_ExpenseExampleYear01 $ 129
3 Years rr_ExpenseExampleYear03 403
5 Years rr_ExpenseExampleYear05 697
10 Years rr_ExpenseExampleYear10 $ 1,534
Annual Return 2007 rr_AnnualReturn2007 (3.64%)
Annual Return 2008 rr_AnnualReturn2008 (29.04%)
Annual Return 2009 rr_AnnualReturn2009 21.43%
Annual Return 2010 rr_AnnualReturn2010 17.47%
Annual Return 2011 rr_AnnualReturn2011 6.79%
Annual Return 2012 rr_AnnualReturn2012 11.02%
Annual Return 2013 rr_AnnualReturn2013 29.79%
Annual Return 2014 rr_AnnualReturn2014 7.85%
Annual Return 2015 rr_AnnualReturn2015 (0.73%)
Annual Return 2016 rr_AnnualReturn2016 21.59%
Highest Quarterly Return, Label rr_HighestQuarterlyReturnLabel Best Quarter
Highest Quarterly Return, Date rr_BarChartHighestQuarterlyReturnDate Jun. 30, 2009
Highest Quarterly Return rr_BarChartHighestQuarterlyReturn 16.68%
Lowest Quarterly Return, Label rr_LowestQuarterlyReturnLabel Worst Quarter
Lowest Quarterly Return, Date rr_BarChartLowestQuarterlyReturnDate Dec. 31, 2008
Lowest Quarterly Return rr_BarChartLowestQuarterlyReturn (21.88%)
1 Year rr_AverageAnnualReturnYear01 21.59%
5 Years rr_AverageAnnualReturnYear05 13.41%
10 Years rr_AverageAnnualReturnYear10 6.93%
Investor Shares [Member] | FAM Equity-Income Fund | Investor Class | after taxes on distributions  
Risk/Return: rr_RiskReturnAbstract  
1 Year rr_AverageAnnualReturnYear01 18.93%
5 Years rr_AverageAnnualReturnYear05 11.71%
10 Years rr_AverageAnnualReturnYear10 5.74%
Investor Shares [Member] | FAM Equity-Income Fund | Investor Class | after taxes on distributions and sale of fund shares  
Risk/Return: rr_RiskReturnAbstract  
1 Year rr_AverageAnnualReturnYear01 14.30%
5 Years rr_AverageAnnualReturnYear05 10.61%
10 Years rr_AverageAnnualReturnYear10 5.34%
Investor Shares [Member] | FAM Equity-Income Fund | Investor Class | Russell MidCap Index  
Risk/Return: rr_RiskReturnAbstract  
1 Year rr_AverageAnnualReturnYear01 13.80%
5 Years rr_AverageAnnualReturnYear05 14.72%
10 Years rr_AverageAnnualReturnYear10 7.86%
Investor Shares [Member] | FAM Equity-Income Fund  
Risk/Return: rr_RiskReturnAbstract  
Risk/Return [Heading] rr_RiskReturnHeading
Objective [Heading] rr_ObjectiveHeading
Objective, Primary [Text Block] rr_ObjectivePrimaryTextBlock
Expense [Heading] rr_ExpenseHeading
Expense Narrative [Text Block] rr_ExpenseNarrativeTextBlock
Shareholder Fees Caption [Text] rr_ShareholderFeesCaption
Operating Expenses Caption [Text] rr_OperatingExpensesCaption
Portfolio Turnover [Heading] rr_PortfolioTurnoverHeading
Portfolio Turnover [Text Block] rr_PortfolioTurnoverTextBlock
Portfolio Turnover, Rate rr_PortfolioTurnoverRate 26.21%
Expenses Restated to Reflect Current [Text] rr_ExpensesRestatedToReflectCurrent "Other Expenses" have been restated based on current contractual arrangements and are estimated for the current fiscal year`.
Expense Example [Heading] rr_ExpenseExampleHeading
Expense Example Narrative [Text Block] rr_ExpenseExampleNarrativeTextBlock
Expense Example by, Year, Caption [Text] rr_ExpenseExampleByYearCaption
Strategy [Heading] rr_StrategyHeading
Strategy Narrative [Text Block] rr_StrategyNarrativeTextBlock
Risk [Heading] rr_RiskHeading
Risk Narrative [Text Block] rr_RiskNarrativeTextBlock
Risk Lose Money [Text] rr_RiskLoseMoney the value of your investment will go up and down, which means that you could lose money.
Bar Chart and Performance Table [Heading] rr_BarChartAndPerformanceTableHeading
Performance Narrative [Text Block] rr_PerformanceNarrativeTextBlock
Performance Information Illustrates Variability of Returns [Text] rr_PerformanceInformationIllustratesVariabilityOfReturns The bar chart shows changes in the Investor Shares performance since 2007. The table shows the Investor Shares average annual returns (before and after taxes ) for the one year, five year and ten year periods compared to those of the Russell MidCap Index, the Fund's primary benchmark index.
Performance Availability Website Address [Text] rr_PerformanceAvailabilityWebSiteAddress famfunds.com
Performance Past Does Not Indicate Future [Text] rr_PerformancePastDoesNotIndicateFuture The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.
Bar Chart Closing [Text Block] rr_BarChartClosingTextBlock


  

Best Quarter 2Q'09 16.68%

 

Worst Quarter

4Q'08 -21.88%

 

Performance Table Heading rr_PerformanceTableHeading
Performance Table Uses Highest Federal Rate rr_PerformanceTableUsesHighestFederalRate The after-tax returns shown in the table are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.
Performance Table Not Relevant to Tax Deferred rr_PerformanceTableNotRelevantToTaxDeferred Actual after-tax returns depend on the investor's tax situation and maydiffer from those shown. The after-tax returns are not relevant to investors who hold their Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts, or to investors who are tax exempt.
Performance Table Narrative rr_PerformanceTableNarrativeTextBlock

Risk_Return Summary - (FAM Small Cap Fund Investor Shares)
v3.7.0.1
Investor Shares [Member] | FAM Small Cap Fund
Shareholder Fees - {FAM Small Cap Fund Investor Shares}
Investor Shares [Member]
FAM Small Cap Fund
Investor
Maximum sales charge (load) on purchase none
Maximum deferred sales charge (load) none
Redemption fee none
Annual Fund Operating Expenses - {FAM Small Cap Fund Investor Shares}
Investor Shares [Member]
FAM Small Cap Fund
Investor
Management Fees 0.90%
Distribution and Service (12b-1) Fees none
Other Expenses 0.46%
Acquired Fund Fees and Expenses 0.02%
Total Fund Operating Expenses 1.38%
Expense Example- {FAM Small Cap Fund Investor Shares}
1 Year
3 Years
5 Years
10 Years
Investor Shares [Member] | FAM Small Cap Fund | Investor | USD ($) 140 437 755 1,657
Bar Chart

Best Quarter

12-31-14

12.35%

Worst Quarter

09-30-15

-9.55%

Average Annual Total Returns- {FAM Small Cap Fund Investor Shares} - Investor Shares [Member] - FAM Small Cap Fund - Investor
1 Year
Since Inception
Inception Date
Before Taxes 24.21% 14.95% Mar. 01, 2012
after taxes on distributions 23.37% 14.33%  
after taxes on distributions and sale of fund shares 15.21% 12.30%  
Russell 2000 Index 21.31% 12.70%  

Risk_Return Detail Data - (FAM Small Cap Fund Investor Shares)
v3.7.0.1
Label Element Value
Risk/Return: rr_RiskReturnAbstract  
Registrant Name dei_EntityRegistrantName FENIMORE ASSET MANAGEMENT TRUST
Prospectus Date rr_ProspectusDate May 01, 2017
Investor Shares [Member] | FAM Small Cap Fund | Investor  
Risk/Return: rr_RiskReturnAbstract  
Maximum sales charge (load) on purchase rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
Maximum deferred sales charge (load) rr_MaximumDeferredSalesChargeOverOther none
Redemption fee rr_RedemptionFeeOverRedemption none
Management Fees rr_ManagementFeesOverAssets 0.90%
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Other Expenses rr_OtherExpensesOverAssets 0.46%
Acquired Fund Fees and Expenses rr_AcquiredFundFeesAndExpensesOverAssets 0.02%
Total Fund Operating Expenses rr_ExpensesOverAssets 1.38%
1 Year rr_ExpenseExampleYear01 $ 140
3 Years rr_ExpenseExampleYear03 437
5 Years rr_ExpenseExampleYear05 755
10 Years rr_ExpenseExampleYear10 $ 1,657
Annual Return 2013 rr_AnnualReturn2013 40.49%
Annual Return 2014 rr_AnnualReturn2014 5.58%
Annual Return 2015 rr_AnnualReturn2015 (3.49%)
Annual Return 2016 rr_AnnualReturn2016 24.21%
Highest Quarterly Return, Label rr_HighestQuarterlyReturnLabel Best Quarter
Highest Quarterly Return, Date rr_BarChartHighestQuarterlyReturnDate Dec. 31, 2014
Highest Quarterly Return rr_BarChartHighestQuarterlyReturn 12.35%
Lowest Quarterly Return, Label rr_LowestQuarterlyReturnLabel Worst Quarter
Lowest Quarterly Return, Date rr_BarChartLowestQuarterlyReturnDate Sep. 30, 2015
Lowest Quarterly Return rr_BarChartLowestQuarterlyReturn (9.55%)
1 Year rr_AverageAnnualReturnYear01 24.21%
Since Inception rr_AverageAnnualReturnSinceInception 14.95%
Inception Date rr_AverageAnnualReturnInceptionDate Mar. 01, 2012
Investor Shares [Member] | FAM Small Cap Fund | Investor | after taxes on distributions  
Risk/Return: rr_RiskReturnAbstract  
1 Year rr_AverageAnnualReturnYear01 23.37%
Since Inception rr_AverageAnnualReturnSinceInception 14.33%
Investor Shares [Member] | FAM Small Cap Fund | Investor | after taxes on distributions and sale of fund shares  
Risk/Return: rr_RiskReturnAbstract  
1 Year rr_AverageAnnualReturnYear01 15.21%
Since Inception rr_AverageAnnualReturnSinceInception 12.30%
Investor Shares [Member] | FAM Small Cap Fund | Investor | Russell 2000 Index  
Risk/Return: rr_RiskReturnAbstract  
1 Year rr_AverageAnnualReturnYear01 21.31%
Since Inception rr_AverageAnnualReturnSinceInception 12.70%
Investor Shares [Member] | FAM Small Cap Fund  
Risk/Return: rr_RiskReturnAbstract  
Risk/Return [Heading] rr_RiskReturnHeading
Objective [Heading] rr_ObjectiveHeading
Objective, Primary [Text Block] rr_ObjectivePrimaryTextBlock
Expense [Heading] rr_ExpenseHeading
Expense Narrative [Text Block] rr_ExpenseNarrativeTextBlock
Shareholder Fees Caption [Text] rr_ShareholderFeesCaption
Operating Expenses Caption [Text] rr_OperatingExpensesCaption
Portfolio Turnover [Heading] rr_PortfolioTurnoverHeading
Portfolio Turnover [Text Block] rr_PortfolioTurnoverTextBlock
Portfolio Turnover, Rate rr_PortfolioTurnoverRate 26.44%
Expense Example [Heading] rr_ExpenseExampleHeading
Expense Example Narrative [Text Block] rr_ExpenseExampleNarrativeTextBlock
Expense Example by, Year, Caption [Text] rr_ExpenseExampleByYearCaption
Strategy [Heading] rr_StrategyHeading
Strategy Narrative [Text Block] rr_StrategyNarrativeTextBlock
Risk [Heading] rr_RiskHeading
Risk Narrative [Text Block] rr_RiskNarrativeTextBlock
Risk Lose Money [Text] rr_RiskLoseMoney the value of your investment will go up and down, which means that you could lose money.
Risk Nondiversified Status [Text] rr_RiskNondiversifiedStatus Non-diversification Risk – the Fund is classified as a "non-diversified" fund which means that the Fund may own larger positions in a smaller number of issuers. A fund that is less diversified, such as the Fund, may be more susceptible to adverse economic, political, or regulatory developments affecting a single issuer than a fund that is more broadly diversified.
Bar Chart and Performance Table [Heading] rr_BarChartAndPerformanceTableHeading
Performance Narrative [Text Block] rr_PerformanceNarrativeTextBlock
Performance Information Illustrates Variability of Returns [Text] rr_PerformanceInformationIllustratesVariabilityOfReturns The bar chart shows the Investor Shares performance since 2013. The table shows the Investor Shares average annual returns (before and after taxes) for the one year period ended December 31, 2016 and since the Fund's inception on March 1, 2012 compared to those of the Russell 2000 Index, the Fund's primary benchmark.
Performance Availability Website Address [Text] rr_PerformanceAvailabilityWebSiteAddress famfunds.com
Performance Past Does Not Indicate Future [Text] rr_PerformancePastDoesNotIndicateFuture The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.
Bar Chart Closing [Text Block] rr_BarChartClosingTextBlock

Best Quarter

12-31-14

12.35%

Worst Quarter

09-30-15

-9.55%

Performance Table Heading rr_PerformanceTableHeading
Performance Table Uses Highest Federal Rate rr_PerformanceTableUsesHighestFederalRate The after-tax returns shown in the table are calculated using the historical highest individual federal marginal income tax rates, and do not reflect the impact of state and local taxes.
Performance Table Not Relevant to Tax Deferred rr_PerformanceTableNotRelevantToTaxDeferred Actual after-tax returns depend on the investor's tax situation and may differ from those shown. The after-tax returns are not relevant to investors who hold their Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts, or to investors who are tax exempt.
Performance Table Narrative rr_PerformanceTableNarrativeTextBlock